Analog data generating and processing device for use with a personal computer

ABSTRACT

An interface device ( 10 ) provides fast data communication between a host device with input/output interfaces and a data transmit/receive device, wherein the interface device ( 10 ) comprises a processor means ( 13 ), a memory means ( 14 ), a first connecting device ( 12 ) for interfacing the host device with the interface device, and a second connecting device ( 15 ) for interfacing the interface device ( 10 ) with the data transmit/receive device. The interface device ( 10 ) is configured by the processor means ( 13 ) and the memory means ( 14 ) in such a way that, when receiving an inquiry from the host device via the first connecting device ( 12 ) as to the type of a device attached to the host device, regardless of the type of the data transmit/receive device, the interface device sends a signal to the host device via the first connecting device ( 12 ) which signals to the host device that it is communicating with an input/output device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/467,073,filed Aug. 24, 2006, which is a continuation of application Ser. No.11/078,778, filed Mar. 11, 2005, now expressly abandoned, which is acontinuation of application Ser. No. 10/219,105, filed Aug. 15, 2002,now U.S. Pat. No. 6,895,449, which is a divisional of application Ser.No. 09/331,002, filed Jun. 14, 1999, now U.S. Pat. No. 6,470,399.

FIELD OF THE INVENTION

The present invention relates to the transfer of data and in particularto interface devices for communication between a computer or host deviceand a data transmit/receive device from which data is to be acquired orwith which two-way communication is to take place.

BACKGROUND OF THE INVENTION

Existing data acquisition systems for computers are very limited intheir areas of application. Generally such systems can be classifiedinto two groups.

In the first group host devices or computer systems are attached bymeans of an interface to a device whose data is to be acquired. Theinterfaces of this group are normally standard interfaces which, withspecific driver software, can be used with a variety of host systems. Anadvantage of such interfaces is that they are largely independent of thehost device. However, a disadvantage is that they generally require verysophisticated drivers which are prone to malfunction and which limitdata transfer rates between the device connected to the interface andthe host device and vice versa. Further, it is often very difficult toimplement such interfaces for portable systems and they offer fewpossibilities for adaptation with the result that such systems offerlittle flexibility.

The devices from which data is to be acquired cover the entireelectrical engineering spectrum. In a typical case, it is assumed that acustomer who operates, for example, a diagnostic radiology system in amedical engineering environment reports a fault. A field servicetechnician of the system manufacturer visits the customer and readssystem log files generated by the diagnostic radiology system by means aportable computer or laptop for example. If the fault cannot belocalized or if the fault is intermittent, it will be necessary for theservice technician to read not only an error log file but also data fromcurrent operation. It is apparent that in this case fast data transferand rapid data analysis are necessary.

Another case requiring the use of an interface could be, for example,when an electronic measuring device, e.g. a multimeter, is attached to acomputer system to transfer the data measured by the multimeter to thecomputer. Particularly when long-term measurements or large volumes ofdata are involved is it necessary for the interface to support a highdata transfer rate.

From these randomly chosen examples it can be seen that an interface maybe put to totally different uses. It is therefore desirable that aninterface be sufficiently flexible to permit attachment of verydifferent electrical or electronic systems to a host device by means ofthe interface. To prevent operator error, it is also desirable that aservice technician is not required to operate different interfaces indifferent ways for different applications but that, if possible, auniversal method of operating the interface be provided for a largenumber of applications.

To increase the data transfer rates across an interface, the routechosen in the second group of data acquisition systems for the interfacedevices was to specifically match the interface very closely toindividual host systems or computer systems. The advantage of thissolution is that high data transfer rates are possible. However, adisadvantage is that the drivers for the interfaces of the second groupare very closely matched to a single host system with the result thatthey generally cannot be used with other host systems or their use isvery ineffective. Further, such types of interface have the disadvantagethat they must be installed inside the computer casing to achievemaximum data transfer rates as they access the internal host bus system.They are therefore generally not suitable for portable host systems inthe form of laptops whose minimum possible size leaves little internalspace to plug in an interface card.

A solution to this problem is offered by the interface devices of IOtech(business address: 25971 Cannon Road, Cleveland, Ohio 44146, USA) whichare suitable for laptops such as the WaveBook/512 (registeredtrademark). The interface devices are connected by means of a plug-incard, approximately the size of a credit card, to the PCMCIA interfacewhich is now a standard feature in laptops. The plug-in card convertsthe PCMCIA interface into an interface known in the art as IEEE 1284.The said plug-in card provides a special printer interface which isenhanced as regards the data transfer rate and delivers a data transferrate of approximately 2 MBps as compared with a rate of approx. 1 MBpsfor known printer interfaces. The known interface device generallyconsists of a driver component, a digital signal processor, a buffer anda hardware module which terminates in a connector to which the devicewhose data is to be acquired is attached. The driver component isattached directly to the enhanced printer interface thus permitting theknown interface device to establish a connection between a computer andthe device whose data is to be acquired.

In order to work with the said interface, an interface-specific drivermust be installed on the host device so that the host device cancommunicate with the digital signal processor of the interface card. Asdescribed above, the driver must be installed on the host device. If thedriver is a driver developed specifically for the host device, a highdata transfer rate is achieved but the driver cannot be easily installedon a different host system. However, if the driver is a general driverwhich is as flexible as possible and which can be used on many hostdevices, compromises must be accepted with regard to the data transferrate.

Particularly in an application for multi-tasking systems in whichseveral different tasks such as data acquisition, data display andediting are to be performed quasi-simultaneously, each task is normallyassigned a certain priority by the host system. A driver supporting aspecial task requests the central processing system of the host devicefor processor resources in order to perform its task. Depending on theparticular priority assignment method and on the driver implementation,a particular share of processor resources is assigned to a special taskin particular time slots. Conflicts arise if one or more drivers areimplemented in such a way that they have the highest priority bydefault, i.e. they are incompatible, as happens in practice in manyapplications. It may occur that both drivers are set to highest prioritywhich, in the worst case, can result in a system crash.

EP 0685799 A1 discloses an interface by means of which severalperipheral devices can be attached to a bus. An interface is connectedbetween the bus of a host device and various peripheral devices. Theinterface comprises a finite state machine and several branches each ofwhich is assigned to a peripheral device. Each branch comprises a datamanager, cycle control, user logic and a buffer. This known interfacedevice provides optimal matching between a host device and a specificperipheral device.

The specialist publication IBM Technical Disclosure Bulletin, Vol. 38,No. 05, page 245; “Communication Method between Devices through FDDInterface” discloses an interface which connects a host device to aperipheral device via a floppy disk drive interface. The interfaceconsists in particular of an address generator, an MFM encoder/decoder,a serial/parallel adapter and a format signal generator. The interfacemakes it possible to attach not only a floppy disk drive but also afurther peripheral device to the FDD host controller of a host device.The host device assumes that a floppy disk drive is always attached toits floppy disk drive controller and communication is initiated if theaddress is correct. However, this document contains no information as tohow communication should be possible if the interface is connected to amulti-purpose interface instead of to a floppy disk drive controller.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide an interface devicefor communication between a host device and a data transmit/receivedevice whose use is host device-independent and which delivers a highdata transfer rate.

The present invention is based on the finding that both a high datatransfer rate and host device-independent use can be achieved if adriver for an input/output device customary in a host device, normallypresent in most commercially available host devices, is utilized.Drivers for input/output devices customary in a host device which arefound in practically all host devices are, for example, drivers for harddisks, for graphics devices or for printer devices. As however the harddisk interfaces in common host devices which can be, for example, IBMPCs, IBM-compatible PCs, Commodore PCs, Apple computers or evenworkstations, are the interfaces with the highest data transfer rate,the hard disk driver is utilized in the preferred embodiment of theinterface device of the present invention. Drivers for other storagedevices such as floppy disk drives, CD-ROM drives or tape drives couldalso be utilized in order to implement the interface device according tothe present invention.

As described in the following, the interface device according to thepresent invention is to be attached to a host device by means of amulti-purpose interface of the host device which can be implemented, forexample, as an SCSI interface or as an enhanced printer interface.Multi-purpose interfaces comprise both an interface card and specificdriver software for the interface card. The driver software can bedesigned so that it can replace the BIOS driver routines. Communicationbetween the host device and the devices attached to the multi-purposeinterface then essentially takes place by means of the specific driversoftware for the multi-purpose interface and no longer primarily bymeans of BIOS routines of the host device. Recently however drivers formulti-purpose interfaces can also already be integrated in the BIOSsystem of the host device as, alongside classical input/outputinterfaces, multi-purpose interfaces are becoming increasingly common inhost devices. It is of course also possible to use BIOS routines inparallel with the specific driver software for the multi-purposeinterface, if this is desired.

The interface device according to the present invention comprises aprocessor means, a memory means, a first connecting device forinterfacing the host device with the interface device, and a secondconnecting device for interfacing the interface device with the datatransmit/receive device. The interface device is configured by theprocessor means and the memory means in such a way that the interfacedevice, when receiving an inquiry from the host device via the firstconnecting device as to the type of a device attached to the hostdevice, sends a signal, regardless of the type of the datatransmit/receive device, to the host device via the first connectingdevice which signals to the host device that it is communicating with aninput/output device. The interface device according to the presentinvention therefore simulates, both in terms of hardware and software,the way in which a conventional input/output device functions,preferably that of a hard disk drive. As support for hard disks isimplemented as standard in all commercially available host systems, thesimulation of a hard disk, for example, can provide hostdevice-independent use. The interface device according to the presentinvention therefore no longer communicates with the host device orcomputer by means of a specially designed driver but by means of aprogram which is present in the BIOS system (Basic Input/Output System)and is normally precisely matched to the specific computer system onwhich it is installed, or by means of a specific program for themulti-purpose interface. Consequently, the interface device according tothe present invention combines the advantages of both groups. On the onehand, communication between the computer and the interface takes placeby means of a host device-specific BIOS program or by means of a driverprogram which is matched to the multi-purpose interface and which couldbe regarded as a “device-specific driver”. On the other hand, the BIOSprogram or a corresponding multi-purpose interface program whichoperates one of the common input/output interfaces in host systems istherefore present in all host systems so that the interface deviceaccording to the present invention is host device-independent.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, preferred embodiments of the present invention will beexplained in more detail with reference to the drawings enclosed, inwhich:

FIG. 1 shows a general block diagram of the interface device accordingto the present invention; and

FIG. 2 shows a detailed block diagram of an interface device accordingto a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It should be understood that the title of this section of thisspecification, namely, “Detailed Description Of The Invention”, relatesto a requirement of the United States Patent Office, and does not imply,nor should be inferred to limit the subject matter disclosed herein.

FIG. 1 shows a general block diagram of an interface device 10 accordingto the present invention. A first connecting device 12 of the interfacedevice 10 can be attached to a host device (not shown) via a host line11. The first connecting device is attached both to a digital signalprocessor 13 and to a memory means 14. The digital signal processor 13and the memory means 14 are also attached to a second connecting device15 by means of bidirectional communication lines (shown for all lines bymeans of two directional arrows). The second connecting device can beattached by means of an output line 16 to a data transmit/receive devicewhich is to receive data from the host device or from which data is tobe read, i.e. acquired, and transferred to the host device. The datatransmit/receive device itself can also communicate actively with thehost device via the first and second connecting device, as described inmore detail in the following.

Communication between the host system or host device and the interfacedevice is based on known standard access commands as supported by allknown operating systems (e.g. DOS, Windows, Unix). Preferably, theinterface device according to the present invention simulates a harddisk with a root directory whose entries are “virtual” files which canbe created for the most varied functions. When the host device systemwith which the interface device according to the present invention isconnected is booted and a data transmit/receive device is also attachedto the interface device 10, usual BIOS routines or multi-purposeinterface programs issue an instruction, known by those skilled in theart as the INQUIRY instruction, to the input/output interfaces in thehost device. The digital signal processor 13 receives this inquiryinstruction via the first connecting device and generates a signal whichis sent to the host device (not shown) again via the first connectingdevice 12 and the host line 11. This signal indicates to the host devicethat, for example, a hard disk drive is attached at the interface towhich the INQUIRY instruction was sent. Optionally, the host device cansend an instruction, known by those skilled in the art as “Test UnitReady”, to the interface device to request more precise detailsregarding the queried device.

Regardless of which data transmit/receive device at the output line 16is attached to the second connecting device, the digital signalprocessor 13 informs the host device that it is communicating with ahard disk drive. If the host device receives the response that a driveis present, it then sends a request to the interface device 10 to readthe boot sequence which, on actual hard disks, normally resides on thefirst sectors of the disk. The digital signal processor 13, whoseoperating system in stored in the memory means 14, responds to thisinstruction by sending to the host device a virtual boot sequence which,in the case of actual drives, includes the drive type, the startingposition and the length of the file allocation table (FAT), the numberof sectors, etc., known to those skilled in the art. Once the hostdevice has received this data, it assumes that the interface device 10according to a preferred embodiment of the present invention is a harddisk drive. In reply to an instruction from the host device to displaythe directory of the “virtual” hard disk drive simulated by theinterface device 10 with respect to the host device, the digital signalprocessor can respond to the host device in exactly the same way as aconventional hard disk would, namely by reading on request the fileallocation table or FAT on a sector specified in the boot sequence,normally the first writable sector, and transferring it to the hostdevice, and subsequently by transferring the directory structure of thevirtual hard disk. Further, it is possible that the FAT is not readuntil immediately prior to reading or storing the data of the “virtual”hard disk and not already at initialization.

In a preferred embodiment of the present invention, the digital signalprocessor 13, which need not necessarily be implemented as a digitalsignal processor but may be any other kind of microprocessor, comprisesa first and a second command interpreter. The first command interpretercarries out the steps described above whilst the second commandinterpreter carries out the read/write assignment to specific functions.If the user now wishes to read data from the data transmit/receivedevice via the line 16, the host device sends a command, for example“read file xy”, to the interface device. As described above, theinterface device appears to the host device as a hard disk. The secondcommand interpreter of the digital signal processor now interprets theread command of the host processor as a data transfer command, bydecoding whether “xy” denotes, for example, a “real-time input” file, a“configuration” file or an executable file, whereby the same begins totransfer data from the data transmit/receive device via the secondconnecting device to the first connecting device and via the line 11 tothe host device.

Preferably, the volume of data to be acquired by a data transmit/receivedevice is specified in a configuration file described in the followingby the user specifying in the said configuration file that a measurementis to last, for example, five minutes. To the host device the “real-timeinput” file then appears as a file whose length corresponds to theanticipated volume of data in those five minutes. Those skilled in theart know that communication between a processor and a hard disk consistsof the processor transferring to the hard disk the numbers of the blocksor clusters or sectors whose contents it wishes to read. By reference tothe FAT the processor knows which information is contained in whichblock. In this case, communication between the host device and theinterface device according to the present invention therefore consistsof the very fast transfer of block numbers and preferably of blocknumber ranges because a virtual “real-time input” file will not befragmented. If the host device now wants to read the “real-time input”file, it transfers a range of block numbers to the interface device,whereupon data commences to be received via the second connecting deviceand data commences to be sent to the host device via the firstconnecting device.

In addition to the digital signal processor instruction memory, whichcomprises the operating system of the digital signal processor and canbe implemented as an EPROM or EEPROM, the memory means 14 can have anadditional buffer for purposes of synchronizing data transfer from thedata transmit/receive device to the interface device 10 and datatransfer from the interface device 10 to the host device.

Preferably, the buffer is implemented as a fast random access memory orRAM buffer.

Further, from the host device the user can also create a configurationfile, whose entries automatically set and control various functions ofthe interface device 10, on the interface device 10 which appears to thehost device as a hard disk. These settings can be, for example, gain,multiplex or sampling rate settings. By creating and editing aconfiguration file, normally a text file which is simple to understandwith little prior knowledge, users of the interface device 10 are ableto perform essentially identical operator actions for almost any datatransmit/receive devices which can be attached to the second connectingdevice via the line 16, thus eliminating a source of error arising fromusers having to know many different command codes for differentapplications. In the case of the interface device 10 according to thepresent invention it is necessary for users to note the conventions ofthe configuration file once only in order to be able to use theinterface device 10 as an interface between a host device and almost anydata transmit/receive device.

As a result of the option of storing any files in agreed formats in thememory means 14 of the interface device 10, taking into account themaximum capacity of the memory means, any enhancements or evencompletely new functions of the interface device 10 can be quicklyimplemented. Even files executable by the host device, such as batchfiles or executable files (BAT or EXE files), and also help files can beimplemented in the interface device, thus achieving independence of theinterface device 10 from any additional software (with the exception ofthe BIOS routines) of the host device. On the one hand, this avoidslicensing and/or registration problems and, on the other hand,installation of certain routines which can be frequently used, forexample an FFT routine to examine acquired time-domain data in thefrequency domain, is rendered unnecessary as the EXE files are alreadyinstalled on the interface device 10 and appear in the virtual rootdirectory, by means of which the host device can access all programsstored on the interface device 10.

In a preferred embodiment of the present invention in which theinterface device 10 simulates a hard disk to the host device, theinterface device is automatically detected and readied for operationwhen the host system is powered up or booted. This corresponds to theplug-and-play standard which is currently finding increasinglywidespread use. The user is no longer responsible for installing theinterface device 10 on the host device by means of specific driverswhich must also be loaded; instead the interface device 10 isautomatically readied for operation when the host system is booted.

For persons skilled in the art it is however obvious that the interfacedevice 10 is not necessarily signed on when the computer system ispowered up but that a special BIOS routine or a driver for amulti-purpose interface can also be started on the host device duringcurrent operation of the computer system in order to sign on or mountthe interface device 10 as an additional hard disk. This embodiment issuitable for larger workstation systems which are essentially neverpowered down as they perform, e.g. mail functions or monitor processeswhich run continuously, for example, in multi-tasking environments.

In the interface device according to the present invention an enormousadvantage is to be gained, as apparent in the embodiment described inthe following, in separating the actual hardware required to attach theinterface device 10 to the data transmit/receive device from thecommunication unit, which is implemented by the digital signal processor13, the memory means 14 and the first connecting device 12, as thisallows a plurality of dissimilar device types to be operated in parallelin identical manner. Accordingly, many interface devices 10 can beconnected to a host device which then sees many different “virtual” harddisks. In addition, any modification of the specific hardware symbolizedby the second connecting device 15 can be implemented essentiallywithout changing the operation of the interface device according to thepresent invention. Further, an experienced user can intervene at anytime on any level of the existing second connecting device by making useof the above mentioned option of creating a configuration file or addingor storing new program sections for the second connecting device.

An important advantage of the interface device 10 of the presentinvention is that it also permits extremely high data transfer rates byusing, for data interchange, the host device-own BIOS routines which areoptimized for each host device by the host device manufacturer or BIOSsystem manufacturer, or by using driver programs which are normallyoptimized and included by the manufacturers of multi-purpose interfaces.Furthermore, due to the simulation of a virtual mass storage device, thedata is managed and made available in such a way that it can betransferred directly to other storage media, e.g. to an actual hard diskof the host device without, as it were, intervention of the host deviceprocessor. The only limitation to long-term data transfer at high speedis therefore imposed exclusively by the speed and the size of the massstorage device of the host device. This is the case as the digitalsignal processor 13 already formats the data read by the datatransmit/receive device via the second connecting device 15 into blocksizes suitable for a hard disk of the host device, whereby the datatransfer speed is limited only by the mechanical latency of the harddisk system of the host device. At this point, it should be noted thatnormally data flow from a host device must be formatted in blocks topermit writing to a hard disk and subsequent reading from a hard disk,as known by those skilled in the art.

The said data transfer rate can be increased further by setting up adirect memory access (DMA) or RAM drive in the host system. As thoseskilled in the art know, the setting up of a RAM drive requiresprocessor resources of the host device, with the result that theadvantage of writing the data to a hard disk drive of the host deviceessentially without the need for processor resources is lost.

As described above, a data buffer can be implemented in the memory means14 to permit independence in terms of time of the data transmit/receivedevice attached to the second connecting device from the host deviceattached to the first connecting device. This guarantees error-freeoperation of the interface device 10 even for time-critical applicationsin multi-tasking host systems.

FIG. 2 shows a detailed block diagram of an interface device 10according to the present invention.

A digital signal processor (DSP) 1300 is, in a manner of speaking, theheart of the interface device 10. The DSP can be any DSP but preferablyhas a 20-MB on-chip random access memory (RAM). Certain instructionsets, for example, can be stored in the RAM already integrated in theDSP. An 80-MHz clock generator is attached to the DSP 1300 in order tosynchronize the DSP. The DSP implements a fast Fourier transformation(FFT) in real time and also optional data compression of the data to betransferred from the data transmit/receive device to the host device inorder to achieve greater efficiency and to permit interoperation withhost devices which have a smaller memory.

In the preferred embodiment of the interface device 10 shown in FIG. 2,the first connecting device 12 of FIG. 1 contains the followingcomponents: an SCSI interface 1220 and a 50-pin SCSI connector 1240 forattachment to an SCSI interface present on most host devices or laptops.The SCSI (small computer system interface) interface 1220 translates thedata received via the SCSI connector 1240 into data understood by theDSP 1300, as known by those skilled in the art. Further, the firstconnecting device 12 comprises an EPP (enhanced parallel port) with adata transfer rate of approx. 1 MBps which delivers a more moderate datatransfer rate of 1 MBps by comparison to the data transfer rate of 10MBps of the SCSI interface. The EPP 1260 is connected to a 25-pinD-shell connector 1280 to permit attachment to a printer interface of ahost device for example. Optionally, the first connecting device 12 alsocomprises a 25-pin connector 1282 which permits the attachment of 8digital outputs and 8 digital inputs 1284 at a host device.

Preferably, the second connecting device comprises 8 BNC inputs with thecalibration relay 1505, a block 1510 with 8 device amplifiers with anovervoltage protection of .±.75 V, this block being connected in turn to8 sample/hold (S&H) circuits 1515. The calibration relays are relayswhich permit controlled changeover between a test voltage and acalibration reference voltage. Each sample/hold circuit is connected toa corresponding input of an 8-channel multiplexer 1520 which feeds itsoutput signals via a programmable amplifier 1525 into an analog/digitalconverter (ADC) with 12 bit and 1.25 MHz 1530 and to the DSP 1300. TheADC 1530 is controlled by means of a 20-bit timer 1535, as known bypersons skilled in the art. The programmable amplifier 1525 and the8-channel multiplexer 1520 are controlled via an amplifier channelselection circuit 1540 which is in turn controlled by the DSP 1300.

The complete interface device 10 is supplied with power by an externalAC/DC converter 1800 which delivers a digital supply voltage of .±.5 Vand is attached to a DC/DC converter 1810 which can deliver analogsupply voltages of .±.5 V and .±.15 V as required for the interfacedevice 10. Further, the DC/DC converter controls a precision voltagereference 1820 which controls the 8 BNC inputs 1505 and the ADC 1530 aswell as a digital/analog converter (DAC) 1830 which permits, via anoutput amplifier block with 4 output amplifiers 1840 and a 9-pinconnector 1850, analog output direct from the DSP 1300 to an outputdevice, e.g. printer device or monitor device, which can be attached viathe 9-pin connector 1850, thus providing the option of monitoring thedata transferred to the host device or also, for example, of viewing anFFT to obtain rapid and comprehensive data analysis without usingprocessor time of the host device.

In FIG. 2 the memory means 14 of FIG. 1 is implemented by an EPROM 1400which, in a preferred embodiment of the present invention, contains theoperating system of the digital signal processor 1300. A random accessmemory with an access time of 15 ns and a size of 512 KB or optionally1024 KB 1420 serves as a data buffer to achieve independence in terms oftime of the output line 16 from the output lines 11 a, 11 b and 11 c tothe data transmit/receive device and to the host device respectively. Asdescribed above, in a preferred embodiment of the present invention thedigital signal processor 1300 already contains a 20-KB on-chip RAM 1440which can store certain instruction sets, functions and also smallerapplication software units.

The connection, symbolized by the line 16, of the interface device 10 toany data transmit/receive device implements, by means of the blocks1505-1535, an analog input with a sampling rate of 1.25 MHz andquantization of 12 bits. There are 8 channels with an overvoltageprotection of .±.75 V. By means of the programmable amplifier 1525 thechannels can be programmed independently of each other in voltage rangesup to a maximum of .±.10 V. Unused channels can be grounded internallyto reduce channel intermodulation. The block 1515 is implemented as amonolithic high-precision, high-speed sample/hold amplifier forsimultaneous sampling of all channels. The precision voltage reference1820 provides a high-precision, temperature-compensated monolithicenergy gap voltage reference for auto-calibration of each channel andeach gain. Further, offset fine adjustment for each channel isimplemented by the same.

The blocks 1830, 1840 and 1850 implement a direct analog output for thedigital signal processor 1300, and the DAC 1830 provides a data transferrate of 625 kHz and a quantization of 12 bits. The block 1840 comprises4 channels with a common output latch.

Further, the interface device 10 comprises a digital input/output deviceimplemented by the blocks 1284 and 1282. Here there are 8 digitalinputs, 8 digital outputs with a common latch, and the digital port canbe attached preferably to a side panel of the interface device 10 sothat the port itself can easily be accessed.

The digital signal processor 1300 provides on-board digital dataprocessing. In particular, it is a high-performance DSP with a clockspeed of 80 MHz and a 20-bit timer 1535.

As described above, the first connecting device 12 comprises the SCSIinterface 1220 with a peak transfer rate of 10 MBps. An optionalPCMCIA-to-SCSI adapter permits high-speed communication with laptopcomputers which are desirable and in widespread use, particularly bymobile service technicians. The EPP 1260 with its associated connector1280 permits data transfer at a more moderate rate.

As described above, the interface device 10 is supplied with power bymeans of an external AC/DC adapter which has a universal power input(85-264 VAC, 47-63 Hz). Interference suppression complies with thestandards EN 55022, curve B and FFC, Class B). Further, it is also inaccordance with international safety regulations (TUV, UL, CSA). Theinterface device 10 is externally shielded and achieves a value of 55 dBat 30-60 MHz and a value of approximately 40 dB at 1 GHz, and thereforecomplies with the MILSTD 285-1 standard.

As described above, communication between the host device and themulti-purpose interface can take place not only via drivers forinput/output device customary in a host device which reside in the BIOSsystem of the host device but also via specific interface drivers which,in the case of SCSI interfaces, are known as multi-purpose interfaceASPI (advanced SCSI programming interface) drivers. This ASPI driver,which can also be referred to as an ASPI manager, is specific to aspecial SCSI host adapter, i.e. to a special multi-purpose interface,and is normally included by the manufacturer of the multi-purposeinterface. Generally speaking, this multi-purpose interface driver hasthe task of moving precisely specified SCSI commands from the hostsystem program to the host system SCSI adapter. For this reason, thecommand set is almost identical to that of the SCSI interface itself.Essentially, only status and reset commands for the host adapter havebeen added.

The ASPI driver can be used if the hard disk was not already addressableat boot time or if the SCSI-related BIOS routines of the host computerwere still disabled. Here too, the steps needed to initialize theinterface device, preferably as a virtual hard disk, are similar to thesteps taken when initializing at boot time.

In general terms, the ASPI manager comprises two sides. One side is theproprietary, hardware-oriented side. It is responsible for convertingall commands into a form required by the corresponding multi-purposeinterface. The hardware-oriented side of the ASPI driver is thereforematched to a very specific type of multi-purpose interface or SCSIinterface. The other side is known as the user software side. This sideis totally independent of the proprietary operating characteristics ofthe SCSI adapter and is therefore identical for all SCSI interfaces.This permits SCSI programming which is however independent of theindividual SCSI adapter types.

In contrast to communication between the host device and the interfacedevice according to the present invention on the basis of a BIOS driver,the use of such an ASPI driver for communication between the host deviceand the interface device according to the present invention allowsvarious further possibilities of the SCSI multi-purpose interface to beexploited. In the case described above, the interface device whichpreferably signs on and behaves as a virtual hard disk is detected bythe BIOS driver of the host computer at boot time and is configured as ahard disk. This step does not however support active requests sent bythe interface device to the host computer. If however the virtual harddisk wishes to write data actively to, for example, a hard disk of thehost computer or wishes to initiate communication with the processor ofthe host computer, the host computer must recognize the request of thevirtual hard disk and tolerate a further issuer of instructions on itsbus. If the interface device behaves solely like a virtual hard disk, itwould always receive and never issue commands. The BIOS has noobjections to an additional issuer of commands that actively wishes toplace data on the bus of the host device but the BIOS does not supportthe host device in recognizing corresponding requests of the interfacedevice or in granting the interface device permission to access the bus.

Using the ASPI manager the interface device according to the presentinvention can now obtain active access to an SCSI hard disk of the hostdevice connected to the same SCSI bus which, in contrast to theinterface device, cannot be a virtual but a real SCSI mass storagedevice or also a further interface device according to the presentinvention. Thereupon, the interface device according to the presentinvention can write the desired data to the SCSI hard disk of the hostcomputer totally independently of the host computer or can communicatewith the same in some other manner. The interface device according tothe present invention therefore initially behaves passively as a virtualhard disk and then, as required and using the driver software for themulti-purpose interface, actively on the same SCSI bus. This meanshowever that the interface device according to the present invention,using a driver software for the multi-purpose interface which comprisesthe BIOS routines customary in host devices and simultaneously providesthe option of active participation, can, regardless of the type of thedata transmit/receive device attached to the second connecting device,behave initially as a virtual and at the same time passive hard disk butcan, as required, participate actively on the bus so as to be able toinitiate communication directly with other SCSI hard disks of the hostdevice by bypassing the processor of the host device.

Using a standard interface of a host device, the interface deviceaccording to the present invention permits communication with any hostdevice. By simulating an input/output device to the host device and, ina preferred embodiment, by simulating a virtual mass storage device, theinterface device 10 is automatically supported by all known host systemswithout any additional sophisticated driver software. The simulation ofa freely definable file structure on the “virtual” hard disk providessimple operation and expansion options and, through the implementationof any programs, independence from special software implemented on thehost device. Help files included on the interface device 10 andplug-and-play support ensure ease of use even in portable, flexible hostdevices. Despite the very simple user interface, experienced users arefree at any time to intervene in the functions of the interface device10 on system level. The interface device 10 thus provides a universalsolution which can cover the entire spectrum of possible datatransmit/receive devices.

1. An analog data generating and processing device for use with apersonal computer having at least one multi-purpose interface to whichinquiry signals are periodically sent as to what type of device isoperatively connected thereto, comprising: a connecting device that isto be operatively connected to the multi-purpose interface of thepersonal computer and that is able to receive therefrom the periodicinquiry signals; a circuit that includes a sensor and an analog todigital converter, the circuit being adapted (i) to be exposed to analogwave signals that originate from a source that is external to the analogdata generating and processing device and that is not located insubstantial proximity to the sensor, (ii) to generate one or more setsof analog data therefrom, and (iii) to generate a set of digitizedanalog data that are representative of each one of the sets of analogdata; a processor and a first memory both of which are operativelyconnected to the circuit, the processor being adapted to cause one ormore of the sets of digitized analog data to be stored in the firstmemory irrespective of whether or not the analog data generating andprocessing device has been recognized by the personal computer; theprocessor being further adapted to cause one or more of the sets ofdigitized analog data to be stored in the first memory before theconnecting device is connected to a multi-purpose interface of thepersonal computer; the processor and first memory being adapted toautomatically and without user intervention send a response signal tothe multi-purpose interface of the personal computer after theconnecting device is operatively connected to the multi-purposeinterface and after the connecting device receives at least one periodicinquiry signal therefrom, the response signal informing the personalcomputer that it can automatically and without user interventionrecognize the analog data generating and processing device as being adevice having digital data that is stored therein; the processor andfirst memory being adapted to, after the analog data generating andprocessing device has been automatically recognized by the personalcomputer, and after the connecting device has been coupled to themulti-purpose interface of the personal computer, cause one or more ofthe sets of digitized analog data, including any digitized analog datasets that are generated before the input/output port is connected to themulti-purpose interface of the personal computer, to be transferred tothe personal computer; the analog data generating and processing devicebeing adapted to affect the transfer of one or more of the sets ofdigitized analog data by means of a software driver that is stored in asecond memory of the personal computer without user intervention; aconductive path having a first portion physically connected to theprocessor and a second portion physically connected to the first memory,the first and second portions of the conductive path being contiguousand not electrically disconnected from each other while one or more ofthe digitized analog data sets are being transferred to the personalcomputer; and the processor being further adapted to store one or moreof the sets of digitized analog data in a file system defined within thefirst memory so that each set of digitized analog data can beselectively retrieved therefrom.